What S t Scien ence H e Have W e We Learned ed f from O Our C - - PowerPoint PPT Presentation

What S t Scien ence H e Have W e We Learned ed f from O Our C Combined ed A Airborne e and G Ground-based ed Measurem emen ents o

• f H

HATS G Gases es? J.W. Elkins, F.L. Moore, E. Hintsa, S.A. Montzka, C. Sweeney, E.A. Ray, J.D. Nance, G.S. Dutton, B.D. Hall, D.F. Hurst, B.R. Miller, D. Mondeel and C. Siso

GMAC 2019, Boulder, CO May 22, 2019

Airborne M e Missi ssions and M nd Measu surem emen ents & s & SF6

• Missions started in 1991 for regional polar O3 loss research studies, covered Pacific ocean, moved to CFC replacements and

shorter lived trace gases with PANTHER, UAS Altair and Global Hawk, and global GHG & chemistry studies.

• SF6 added in 1994, identified SF6 mesospheric sink (3200 yr to 850 yr lifetime). Started atmospheric transport studies.

An Ex Example f from Tropospheric S Seasonal Surve very: M Measurem emen ents

• f S

f SF6 on ATmos

• spheri

ric Tomograp aphy Mission ( (Atom)

• ATom had 11-13 flights per circuit

(ATom 1-4), 4-9 vertical profiles per flight.

• Three airborne GMD instruments

(PANTHER, UCATS, and PFPs) used GC-ECD and the WMO CCL standard scale on all circuits.

• PANTHER and UCATS measured SF6
• nce every 70 seconds and not in
• sync. Twice the data! Total ~7700
• bs./circuit.
• PFP typically had 1-2 twelve flask

packages per flight. ~220 obs./circuit.

Using SF SF6 as a a Tropospheric C Clock

• NOAA GMD ground based network measured

SF6 since 1995 from 3.5 to >10 ppt globally.

• Growth rate over the past 5 years was 0.32 ppt

yr-1. Strong N-S gradient. Has lifetime of 850 yr. Great atmospheric clock!

• Used in the electric power distribution, large

growth in usage in East Asia.

• Emitted mainly from 30 to 60○ N.
• Used to show stratospheric delay of peak EESC
• f 3 years in midlatitudes and 5 years in polar

regions for stratospheric ozone depletion.

• First proposed by D. Waugh as a tropospheric

age of the air mass from polluted NH regions. Extremely useful for long term greenhouse and

• zone depleting gases.

Co Comparisons of multiple NOAA i instruments f for S r SF6

• Two separate instruments, MAGIC EC-GC & Perseus

MS-GC, in our Boulder lab measured the same PFPs for SF6 for ATom-1 (a) to within ±0.05 ppt (±2 mon).

• Perseus MS-GC was dropped after ATom-2, because
• f work load issues at NOAA.
• Two airborne GCs measured within ±0.08 ppt (±3

mon) for both circuits but includes atmospheric variability and instrumental precision (b).

• Results give us encouragement for combining sets,

but differences do exist between circuits.

• Created large data combining the two airborne GCs

(UCATS & PANTHER).

a. b.

NH Summer (Aug. 2016): SF6, age, met fields

ATom-1

Older air: Stratosphere Over the top exchange IH Exchange ~1.2 yr

NH Winter (Feb. 2017): SF6, age, met fields

ATom-2

Older air stratosphere in both hemispheres Young SH air moves to NH

NH Spring (May 2018): SF6, age, met fields

ATom-4

Over the top exchange Older air: Stratospheric Stratospheric fold

Dynamics cs & & Chemistr try i in t the Su e Summer ertime St Stratosphere ( e (DCOTSS) (201 2019-2025) 025)

• Deep convective injection of H2O-rich

air above tropopause with O3 loss from catalytic loss halogens in sulfate from volcanos or geoengineering where NA monsoon contains chemistry for a week or more during a period of increasing climate forcing by GHGs.

• Over 19,000 storms between 2004 &

2013 above tropopause (390K).

• UCATS measures H2O & O3, and add a

3rd channel for CCl4 and short lived halocarbons in the upper Q-bay of NASA ER-2. Provides N2O vs O3 for

• zone loss calculations, and total

inorganic bromine and chlorine estimates from UCATS 70 sec and flasks from WAS (E. Atlas, U Miami & E. Apel, NCAR)

NOAA NEXRAD

Summary ry o

• f T

Talk

• Our airborne program and

ground based programs have been complementary, benefiting each other for science.

• SF6 as a ”tropospheric clock”

between source region and SH and stratosphere.

• SF6 and age of polluted NH air

show circulation in the tropics (Hadley cell) and stratospheric exchange in the polar regions.

• Future mission for ozone loss

in NA monsoon preparing for sulfate additions by volcanos

• r geoengineering.

HATS network data available at ftp://ftp.cmdl.noaa.gov/hats All Atom data are available publicly at the NASA ORNL DAAC https://daac.ornl.gov/ATOM/campaign/

DC-8 Off Greenland and open waters

Questions

• We acknowledge our sources
• f airborne research funding.

It takes a “community” for an airborne mission—NASA DC-8 ATom-4